1. Field of the Invention
The invention relates generally to a trigger and method for adjusting a triggering clearance suited for use in fuel shut-off mechanisms of gas turbine engines.
2. Description of the Prior Art
In gas turbine engine assembly, it is not always possible to premachine every part to the exact right dimension prior to assembly because, in some cases, the accuracy required is within the range of the tolerance stack-up on the engine. Thus, the exact dimension can only be ascertained once a group of engine parts come together during assembly. This is problematic as time is wasted in assembly having to disassemble parts in order to accurately machine a particular part to the exact required dimension.
In one particular case, the trigger of the fuel shut-off mechanism needs to be positioned in spaced relation with other engine components to define a triggering clearance that must be very accurately controlled. The accuracy required is often within the range of the tolerance stack-up on the engine, and therefore the trigger must undergo a custom grinding operation during assembly to obtain the required triggering clearance. As the trigger must be very accurately machined, it is not uncommon for grinding error to occur thus further delaying engine assembly. Customization and rework add unwanted cost and time to assembly
Accordingly, there is a desire to provide a method of adjusting a triggering clearance between engine components to reduce wasted time and effort in assembly.